JSFiddle

JSFiddle is an online code playground and collaboration tool for web development that allows developers to test and share HTML, CSS, and JavaScript code snippets in a browser-based editor. It offers separate panels for HTML, CSS, and JavaScript with syntax highlighting, code completion, and support for preprocessors like Babel JSX, TypeScript, CoffeeScript, SCSS, LESS, and Stylus. Users can choose from over 50 popular JavaScript library and framework versions to load automatically, including React, Vue, Angular, jQuery, D3, Bootstrap, and Lodash, making it easy to test code in the exact runtime context needed. The Run button executes all code and renders the output in a preview pane. Fiddles can be saved and shared via a shortened URL, making JSFiddle one of the most widely used platforms for Stack Overflow answers, blog post code examples, and bug reproduction reports. A PRO tier adds private fiddles, asset hosting, and team collaboration features.